The present invention relates to a system and method for recording and reproducing or recording, reproducing and erasing information on an information recording medium such as an optical disk using a light beam and, more particularly, to an optical system for detecting a position of an objective lens in an optical head when an optical head for focusing a light beam on a light reflecting surface of an optical disk is skipped on the optical disk to trace a desired tracking guide using a light beam, thereby preventing the objective lens from vibrating.
In an information recording medium such as an optical disk, information is recorded on a light reflecting surface of a tracking guide extending concentrically or spirally along the circumference of the disk by changing the condition of the light reflecting surface, for example forming pits on the light reflecting space. This recording of information includes preinformation such as a tracking address and a sector address recorded in advance and data information such as an image to be recorded later, and the data information is recorded or reproduced while reading out the preinformation. Further, an objective lens is in general suspended by a leaf spring movable along the optical axial direction and to the direction perpendicular to the optical axis for the control of the focus and the tracking.
When information is reproduced or recorded from a desired tracking guide by skipping from a predetermined position in such an optical head, the optical head is moved at a relatively high speed along the radial direction of the optical disk, for example, by a linear actuator. However, there arises a problem that, when the optical head is moved at a high speed, an objective lens vibrates in the head and, even if the lens is located at a position of a desired tracking guide, the lens continues vibrating so that information cannot be immediately recorded or reproduced.